Research on this project has to do with synthetic oxygen carriers of manganese, iron, and cobalt complexes. These systems are being examined in order to learn what factors improve the oxygen carrying properties of metal complexes. The approach used in this study involves making changes in the equatorial and axial ligands coordinated to the metal centers, and determining the oxygen uptake tendencies which accompany these changes. The study also included obtaining information on the bonding and structures of the dioxygen metal complexes. Our ultimate goal is the preparation of synthetic oxygen carriers that are better than any currently known.